Odontoblast death drives cell-rich zone-derived dental tissue regeneration

Bone. 2021 Sep;150:116010. doi: 10.1016/j.bone.2021.116010. Epub 2021 May 18.

Abstract

Severe dental tissue damage induces odontoblast death, after which dental pulp stem and progenitor cells (DPSCs) differentiate into odontoblast-like cells, contributing to reparative dentin. However, the damage-induced mechanism that triggers this regeneration process is still not clear. We aimed to understand the effect of odontoblast death without hard tissue damage on dental regeneration. Herein, using a Cre/LoxP-based strategy, we demonstrated that cell-rich zone (CZ)-localizing Nestin-GFP-positive and Nestin-GFP-negative cells proliferate and differentiate into odontoblast-like cells in response to odontoblast depletion. The regenerated odontoblast-like cells played a role in reparative dentin formation. RNA-sequencing analysis revealed that the expression of odontoblast differentiation- and activation-related genes was upregulated in the pulp in response to odontoblast depletion even without damage to dental tissue. In this regenerative process, the expression of type I parathyroid hormone receptor (PTH1R) increased in the odontoblast-depleted pulp, thereby boosting dentin formation. The levels of PTH1R and its downstream mediator, i.e., phosphorylated cyclic AMP response element-binding protein (Ser133) increased in the physically damaged pulp. Collectively, odontoblast death triggered the PTH1R cascade, which may represent a therapeutic target for inducing CZ-mediated dental regeneration.

Keywords: Cell-rich zone; Dental tissue regeneration; Nestin; Odontoblast; Odontoblast-like cell; PTH1R.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Differentiation
  • Dental Pulp
  • Dentin*
  • Odontoblasts*
  • Stem Cells
  • Wound Healing